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Tue Apr 04, 2006 7:26 pm

I'm currently running with an Empi style breather box, (Sponge in box) that seems to be doing the job, but was wondering if I'm missing some kind of benefit by not running a hose to one of my Kadron carbs.
Is it strictly an enviromental thing, or does it actually breathe better?
I have the stock oil filler, so am I begging for fouled plugs and gummed up carb if I do? What if I kept the empi box for the valve covers, will that relieve some of the dreaded oil in carb action?
Is it even worth it? Please educate me. Thanks

Tue Apr 04, 2006 7:32 pm

I have my breather box vented to the air. The hose runs into the right fender through the old charcoal box hose hole.

Tue Apr 04, 2006 7:35 pm

So your avoiding the carb option? Why?

Tue Apr 04, 2006 7:41 pm

It's not a daily driver so i'm not concerned with the emissions.

Also years ago when i vented to a carb, that air cleaner always had oil in it.

Finally I once had a air filter ignite and start a fire. I'll give you one guess which air cleaner it was............

Tue Apr 04, 2006 7:52 pm

Not.
use a breather box.
Oil will not burn,but it will foul the plugs!!!
stock vw's have it for smog.

Tue Apr 04, 2006 7:53 pm

Since the breather system you have is basically just an open system and dumps alot of hydrocarbons in the air, putting a hose to the top of the kadron does absolutely nothing.

if you look closely at your empi breather its not even a sealed box. There would be so little vacuum signal coming from the carb your not gaining anything.

I have that same sponge filled aluminum breather box and its basically an oil catch. It is sitting high up since blowby will be going from the valve covers via hose to the breather "oil catcher". Thats all its purpose is.

The term breather is just basically stating "the hell with an evaporative system lets dump hydrocarbon vapor/fumes to the atomsphere" :wink:

it is what it is. Putting a hose at the top of a carb is a waste of time.

Tue Apr 04, 2006 8:27 pm

Wow - Glenn, A.J. and Alen have spoken, I'm honored. A little surprised at the answers though. Seems after checking out about a cazillion engine photos, I've taken note of alot of elaborate ways inwhich others have tried to tie into their air cleaners,( drilled into,tapped, bizarre fittings combos...) all to pull off this breather into the carb thing. Thought for sure there was something to it.

Thanks for bottom line on this, I'm learning! 8)

Wed Apr 05, 2006 2:33 pm

So, what you guys are saying is that I dont NEED to run the hose to the carbs? Just as long as I do have a way to vent, it's doesn't matter if it's hooked to the open air or the valve covers or the carbs?

Wed Apr 05, 2006 3:01 pm

1x to each valve cover.
1x from the oil filler. Thats it.
To a breather box.
if the car will se any drag strips than make it a 1qt breather box. (NHRA ruel) :shock:

Tue Oct 06, 2009 1:33 pm

I have this same empi box mounted on my car. It is plumbed with the 2 side ports going to valve covers and front facing port to the oil filler tube.
When I had this setup on a 1600 the box seemed to work just fine with just the lid vented (lid being spaced off the box by the tabs). Of course every few weeks I would take the lid off and wring out the foam and soak up the water and oil out of the box.
Recently I put a 2110 in the car. Now the box wants to blow that messy oily water out the lid vents and all over the engine daily. I am thinking of grinding down the tabs on the box so the lid actually seals and installing another port in the lid to run a line over to one of the carbs or both if needed. Does that sound like it will resolve my problem or am I headed down the wrong road??

Tue Oct 06, 2009 3:11 pm

I use the same empi box in my T4 bus but opted to modify the box to run hoses to the air cleaners. No scientific testing, just felt it would be better to have any excess blowby go towards the carbs rather than to the atmostsphere/hot air system. I situated the air cleaner fittings at the 3o'clock/9o'clock postion on the IDF filters so there is no direct flow into the velocity stacks. Haven't noticed any significant buildup of oil on the fliter's bottom plate.

The top plate sits off of the bottom box by a couple of tabs which are easily filed off so the two pieces mate up. Originally made a cork gasket but then just went with some Loctite 518 sealer. Drilled and tapped the top plate and screwed in two 90 degree barbed hose fittings. I'm sure one would be enough but at the time I was thinking 3 hoses in should have more than one out.

Toss the foam but keep the drilled plate and instead fill the unit with copper pot cleaning scrubbers both above and below the plate. With a T4 the stock air breather is already baffled so I plugged up the rear facing inlet and replaced it with another 90 degree fitting located higher up on the box portion so the excess oil would drain out the fitting to the heads rather than back into the stock air breather. Also found it better to not use the o-rings around the inlet fittings; permatex pipe sealer with teflon worked better.

BTW don't use the hose supplied except to run lines to the air cleaners. Stuff split open at the heads a couple of times making a mess before I tossed and purchased some proper hose. And if you overtorque the breather box lid's bolts and snap off the bolt tab you can wrap the box lid with 4 hose clamps and use them to torque down the lid.

Tue Oct 06, 2009 4:14 pm

I was under impression that vw plumbed oil filler to aircleaner to offset pressure difference from the crank case as engine size increased and road draft tube was not enough. For emissions road draft tube was removed.

Tue Oct 06, 2009 4:19 pm

It was mainly for emissions.
Most people seem to believe that attaching it to the aircleaner will cause the crankcase pressure to become lower due to suction.
But unless your filter is extreamly clogged up this will never happen.

Tue Oct 06, 2009 11:13 pm

I have mine vented from my CB tower to my 1/2 side carb. I have no oily filter issues, or fouled plugs. I have however, been told that venting to the carb dilutes the octane level in the fuel. I have seen no evidence of it, as I have had zero issues.

Wed Oct 07, 2009 9:04 am

i have my breather box vented to one carb, both valve covers, leaving one port blocked on the breather box, and then vent the oil filler to a pan evac on my sidewinder, so i am pulling air through the breather box from the air filter, through the engine and then out through the exhaust. works fantastic, my oil is staying cleaner much longer and i get no engine smell into my heating system, and also driving around town in cold weather i have eliminated the spooge from water condensation in the case, probably not epa approved.

Wed Oct 07, 2009 11:21 am

A.J.Sims wrote: Not.
use a breather box.
Oil will not burn,but it will foul the plugs!!!
stock vw's have it for smog.

ok, I guess diesels don't run either...

Wed Oct 07, 2009 11:26 am

OK - I am confused on this - many cars (not just VWs) that I have seen run a line from the valve cover to the aircleaner. It would seem that any oil vapor that makes it there gets sucked into the carb and is burned. Also, by running a line to the top inside of the aircleaner, would you not also get somewhat of a scavenging effect for the oil vapor?

I am not disagreeing with the experts, just trying to understand the issue better. Thanks.

Wed Oct 07, 2009 1:29 pm

The reason OEM's are (forced) to do it is emissions. Crankcase vapors are routed from the rocker box to the intake tract via the PCV valve, to be burned in the cylinders. You can also run an evacupan/evacusump system to draw the vapors out of the crankcase via a small venturi in the tailpipe, but most just run the breather box.

Wed Oct 07, 2009 1:47 pm

I think it was "raygreenwood" who wrote an indepth post about how to properly extract crankcase fumes - could be in the t4rum section of another forum if you can't find it here. Basically air gets pulled out from behind the air filters (so its filtered) into the heads, down the PR tubes into the block then sucked out via a small hose connection under the throttle plates. His post goes deeper into the details.

Thu Oct 08, 2009 2:26 pm

this was not originally an emission driven design !!
I have cars with the breather hose returning to the air cleaner that are well before any EPA rules..

To my understanding this began as a means of reducing the visual and smelly oil vapors that were being emitted by military vehicles during WWII, ( Very detectable by opposing forces) it was discovered that engine service life nearly doubled as a result of this change...

The oil vapor does aid in top end lubrication, however as the VW's are in a boxer configuration, and the valves are not at the very top of the motor, im not sure of any real gain here..